An interesting item of news concerning Aquaflow, the Blenheim algae farming company written about previously on Hot Topic here and here. They are combining efforts with another South Island company Solray Energy on the conversion of the harvested algae into fuel.
The Aquaflow operation in the Marlborough sewage ponds does two things – produces wild algae biomass from which oil can be extracted, and at the same time results in a discharged water which has been cleaned by the process to WHO irrigation standards. The process of converting the biomass to fuel is obviously a key factor in the effectiveness of using naturally occurring algae. Solray has separately developed a reactor and extraction process to detoxify algae and deliver a crude oil and other co-products, with the oil capable of being refined as biofuel. It says it can convert all of the algae – not just the fatty acids – into the crude oil. Their new reactor can process several tonnes of harvested microalgae per day. It sounds a promising partnership.
Meanwhile in other countries, including China, there is a continuing flurry of interest in higher yielding algae, either selected or genetically modified, farmed in controlled constructed environments which are much more capital intensive than that provided by the Marlborough sewage ponds. The yield of oil claimed from such enterprises varies greatly, but it is many times higher than could be gained from growing oil-yielding plants. One company has taken a step further and claims it has a process using genetically engineered microorganisms (which it says are not algae) with a yield considerably higher then even the top algae figures.
Many of these higher tech enterprises rely on an enhanced level of CO2 to achieve optimum growth in the controlled environment. The enthusiastic observation is frequently made that they could be run in tandem with power plants, tapping into the CO2 released as the coal or gas is burned. But such a combination surely puts a question mark over their status as renewable biofuels. The fossil CO2 they use is not sequestered, as some of the reports claim, but merely delayed in its emission . Usefully delayed one might argue, but not contributing to the fossil fuel emissions reduction that biofuels are intended to achieve.
Ventures like that represented by Aquaflow and Solray may be more modest in their expectations but they have better credentials for a world weaned from fossil fuels. Here’s hoping their partnership produces good results.