Algae to Fuels Under Pressure.

The conventional route to biodiesel consists of extracting oil from plants and converting it to the methyl esters of fatty acids that are present in the lipid-components, known as triglycerides. These esters as a mixture constitute biodiesel: a specific kind of biofuel. High oil-yielding strains of algae can be grown and dried and the oil extracted from the dry algal mass, before being similarly converted to biodiesel in a process called transesterification.

Removing the water from raw algae is a highly energy intensive process, and to minimise the overall energy costs of biofuel production from algae, a process called hydrothermal liquefaction may instead be employed in which the algae are not dried but heated under pressure such that the water they contain acts as a chemical reagent and solvent that breaks-down the algal cells and converts not only the oil (lipid) but the sugar and protein component into fuels such as liquid hydrocarbons, gaseous fuels like methane and a complex material called "bio-oil" with a similar energy content to crude oil.

Clearly, the design of engines will need to be adapted in order to use these alternative fuels directly, or they must be refined in a "biorefinery" along with those from other kinds of biomass. In both cases of new engines or biorefineries, there will be huge new engineering required and on a scale that can only be guessed at if really algae can be exploited to make a nation the size of the United States independent of cheap imported crude oil.

Nonetheless, there is a consortium (National Algae Association) in the U.S. that is actively seeking a future in which algae are grown on a large scale and converted to oil-alternative fuels. Certainly, it is likely that algae will become an essential component of the mix of means to keep transportation going by means other than crude oil.

The claims of the NAA are undoubtedly true, that ultimately the supply of petroleum must decline, oil prices will continue to be volatile with knife-edge consequences for the world economy, and a wholesale industry based on algae would provide precious and needed jobs and economic development in the U.S. The approach could be introduced on necessary levels for all nations and even a village "pressure cooker" to provide algal fuels for small communities.

Related Reading.
A. Demirbas, "Use of algae as biofuel sources," Energy Conversion and Management, 2010, 51, 2738-2749.

Carbon Capture and Storage (CCS) - Yay or Nay?

A new paper (1) published in the prestigious American Chemical Society journal, Environmental Science and Technology, has put the cat among the pigeons over carbon capture and storage (CCS). It argues that the colossal amount of money that CCS would entail globally would be better spent on "virtual CCS", meaning per se that instead of actual CCS, the emission of carbon be avoided in the first place by a wholesale implementation of non-fossil energy sources, specifically wind and nuclear power. As a statistic to prove the point, it is estimated that one wedge (billion tonnes) of carbon in the form of CO2 sequestered by CCS would cost $5.1 trillion over 50 years, while the same amount of money used to build wind-turbines would save 1.91 "wedges" worth of CO2 over the lifetime of the windmills. A strong rebuttal to this case is presented in the September Chemistry World (2), which calls for a parallel development of CCS and non-fossil energy rather than the exclusion of the former.

Since 100 million tonnes per DAY of CO2 would need to be so sequestered by CCS the engineering required to bring it to fruition is phenomenal. There are essentially two methods to remove carbon from fuel: post-combustion and pre-combustion. Post-combustion, CO2 is removed from flue gas by passing it through a liquid amine which dissolves the CO2. Pre-combustion, the fuel (coal, gas, biomass) is processed into a mixture of CO2 + H2 and the CO2 is removed. Either way, the CO2 must be put somewhere, for which strategies include pumping it into rocky formations (such as depleted oil and gas wells) at a pressure of 100 atmospheres, or even piping it in liquid form under pressure onto the sea-floor where it is cold enough and the pressure high enough that it is hoped the material will stay there, assisted by the formation of CO2-hydrate.


(1) C Tsouris, D S Aaron and K A Williams, 2010, Environ. Sci. Technol., 44, 4042
(2) http://www.rsc.org/chemistryworld/Issues/2010/September/DoWeReallyNeedCarbonCaptureStorage.asp

So, What Did Happen After the Chinese Oil-Spill?

On the 16th of July, China experienced its first major oil-spill. The Chinese incident was also caused by an explosion (this time during the transfer of oil from a tanker to a reserve owned by the China National Petroleum Corp), but is nothing like the size of the BP spillage in the Gulf of Mexico. The amount of public information released in any level of detail has so far been scant, but in this month's Chemistry World, the British Royal Society of Chemistry has published an article which provides some update of the state of play in the aftermath of the event.

Around 1,500 tonnes of crude-oil ended-up in the Dalian Bay, which is a popular resort for tourism and conferences, located in the far east of China. The initial clean-up was pretty much over in two weeks, but residual problems in safety management are highlighted. As usual, there are various estimates of the size of the resulting oil-slick, of between 150 - 450 square kilometers of ocean covered, but the main concern is that the oil might contain toxic organic contaminants that could invade the food-chain, threatening the health of humans, animals and that of the wider environment for decades to come.

It is argued that a lack of technical expertise and equipment in China made the clean-up process more complicated and protracted than it need have been. Many thousands of workers were garnered in Dalian and simply sent-out in fishing-boats to collect the oil in buckets, which was then poured into storage-tanks. Since they had little or no protective equipment or were untrained in how to use what they did have, the long-term effects of their exposure to a mixture of chemical substances remains to be seen. It appears that the Dalian municipal government had only enough capacity to cope with 200 tonnes of oil, and less than the 1,500 actually spilt.

While this is nothing compared to the 750,000 tonnes of oil that poured into the gulf of Mexico, for which BP are taking part of the blame along with their subcontractors, the point is made that China needs to advance its capability to provide long-term solutions to environmental problems of this kind. There is currently a great lack of environmental and geochemical research into oil-spills in China. The Dalian oil-spill is likely to be a microcosm of greater future catastrophes for a highly populous country that is expected to expand its oil-based personal transportation by a factor of ten to 200 million by 2020.

Related Reading.
"China tackles its first major oil spill," Chemistry World, September 2010, p10.

Australia Plans to be Carbon-Neutral by 2020.

I have just been sent a remarkable document entitled “Zero Carbon Australia Stationary Energy Plan.” As the title implies, within its pages is a proposal for how Australia might be run without the use of fossil fuels, including for transportation, by 2020. The ambitious plan, from a nonprofit called Beyond Zero Emissions and researchers at Melbourne University, hinges on developing enough concentrating solar thermal power (CST) capacity, using molten salt storage to provide a constant supply of energy, to the tune of 60% of the country’s power. The remaining 40% would come from wind farms, along with a smaller element of biomass and hydropower as a back-up. Some 20% of the solar installations would be built by 2014 under the plan and the rest by 2020 to a final generating capacity of 42 GWe.

In a sense, the scheme is similar to the Desertec project, which I posted about on this blog and on Forbes recently, which proposes to use CST based stations in north Africa to provide electricity for Europe. However, the Australian plan is far more inclusive in attempting to satisfy all the energy requirements of a nation of just over 20 million people.

A wholesale electrified transportation system is envisaged, with electric trains and electric vehicles, to offset the 15% of total Australian energy which is used for transport, in the form of oil. Indeed, an increased use of electricity is planned overall by 40%, to an annual 325 TW by 2020. The report insists that, in hand with a combination of energy efficiency and fuel-switching measures, this growth in electricity production would be enough to supplant all fossil fuel use (coal, gas and oil), including that for transport and space-heating. With the loss of inefficient internal combustion engines along with the use of heat-pumps and better insulation in the building sector etc., Australian energy demand is predicted to fall from 3834 Petajoules (1065 TWh) in 2007 to 1643 Petajoules (456 TWh) by 2020.

Transportation is a challenge in its own right. There are around 15 million vehicles on Australia’s roads, and it is practically inconceivable that a similar number of electric vehicles could be made in the remaining years before 2020. The introduction of electric light-railway systems might bear some of the transportation load, but these need to be built from scratch, and within the context of a completely new social infrastructure.

It is proposed that the project will require $35 billion to $40 billion a year over a 10-year period, and that overall this will be net-cost effective given the anticipated rise in oil prices, to the tune of $1.2 trillion. Nonetheless, these are merely indicative figures and there is no clear mandate or promise from either private or public sector as to where the money will come from. The engineering requirement overall for CST, wind-power, new power distribution, electric transportation etc. is phenomenal and unprecedented, and while I marvel at the audacity of the proposal, I doubt very much that it can be done in time, if at all.

Looking for Algal Oil... with Near Infrared Light.

A new method has been introduced for telling which strains of algae are likely to be any good for turning into biofuels based on Near Infrared (NIR) spectroscopy. The near infrared spectrum runs the range of wavelengths 800 - 2500 nm, and is therefore just below the region of visible light but above the usual mid-infrared, at 2,500 - 30,000 nm. The discovery of infrared radiation is attributed to the British/German Astronomer Herschel, who also wrote 24 symphonies. However, NIR only came to practical use in the 1950s as an analytical device. NIR is less sensitive than normal (mid) IR but can penetrate samples more easily meaning they need less analytical preparation and in the case of algae can be examined in their raw state.

Algae very considerably in their composition, and while some varieties contain around 50% of their weight of oil, others hold as little as 5%. Not only this, but the "oil" should contain a high level of fatty acids to be converted into biodiesel: triglycerides rather than phospholipids.

The NIR method is highly specific for the detection of different kinds of fatty acids and it is intended to develop a database of fingerprints for different fatty acid components in algal biomass, with which to analyse actual algae. The method offers the promise of a rapid and precise screening of algae directly rather than the existing time-consuming, cumbersome and error-prone means for analysing algae, and may prove pivotal in the development of a putative fuel industry based on algae.


Related reading.
"Striking algal oil," Chemistry World, By Anna Lewcock. http://www.rsc.org/chemistryworld/News/2010/March/12031001.asp
"Oil from algae; salvation from peak oil," C.J.Rhodes, Science progress, 2010, Vol. 92, 39-90.