Displaying items by tag: Pond Biofuels

One highlight from the cement industry news over the last month was Skyonic's announcement that it has opened a commercial-scale carbon capture unit at the Capitol Aggregates cement plant in Texas, US. Details were light, but the press release promised that the unit was expected to generate US$48m/yr in revenue for an outlay of US$125m. Potentially, the implications for the process are profound, so it is worth considering some of the issues here.

Firstly, it is unclear from the public information released whether the process will actually make a profit. The revenue figures for the Skyonic unit are predictions and are dependent on the markets that the products (sodium biocarbonate, hydrogen and chlorine) will be sold into. Skyonic CEO and founder, Joe Jones, has said in interview that the sodium-based product market by itself could only support 200 - 250 plants worldwide using this process. Worldwide there are over 2000 integrated cement plants. Since Jones is selling his technology his market prediction might well be optimistic. It is also uncertain how existing sodium biocarbonate producers will react to this new source of competition.

Secondly, Skyonic is hoping to push the cost of carbon capture down to US$20/t. Carbon dioxide (CO₂) capture and transportation varies between industries depending on the purity and concentration of the by-product. For example, in 2011 the US Energy Information Administration estimated the cost for CO₂ capture to range from US$36.10/t for coal and biomass-to-liquids conversion up to US$81.08/t for cement plants. The difference being that capturing CO₂ from cement plant flue gas emissions requires more cleaning or scrubbing of other unwanted chemicals such as mercury.

With these limitations in mind, Skyonic is placing itself in competition with the existing flue gas scrubbing market rather than the carbon capture market, since the level of CO₂ removal can be scaled to local legislation. Plus, SO_x, NO₂, mercury and other heavy metals can be removed in the process.

Back on carbon capture, Skyonic is securing finance for a process it calls Skycycle, which will produce calcium-based products from CO₂, with a pilot plant planned at Capitol Aggregates for late 2015. This puts Skyonic back amongst several other pilot projects that are running around the world.

Taiwan Cement and the Industrial Technology Research Institute inaugurated their calcium looping project pilot in mid-2013. It was last reported to have a CO₂ capture rate of 1t/hr.

The Norcem cement plant in Brevik, Norway started in early 2014 to test and compare four different types of post-combustion carbon capture technologies at its pilot unit. These are Aker Solutions Amine Technology, RTI Solid Sorbent Technology, DNV GL/ NTNU/ Yodfat Engineers Membrane Technology and Alstom Power Regenerative Calcium Cycle. The project in conjunction with HeidelbergCement and the European Cement Research Academy (ECRA) is scheduled to run until 2017.

St Marys Cement in St Marys, Canada started its bioreactor pilot project in July 2014. This process uses flue gas to grow algae that can then be used for bio-oil, food, fertiliser and sewage treatment.

If Skyonic is correct then its sodium biocarbonate process in Texas is a strong step towards cutting CO₂ emissions in the cement industry. Unfortunately, it looks like it can only be a step since the market won't support large-scale adoption of this technology. Other pilots are in progress but they are unlikely to gather momentum until legislation forces cement producers to adopt these technologies or someone devises a method that pays for the capture cost.

An update on the algae bioreactor project at Votorantim's St Marys cement plant in Canada this week provides a good opportunity to review this particular aspect of carbon sequestration. The project, run with Pond Biofuels, went live in 2009. It has now reached its third generation bioreactor at the site.

Little or no performance data has been released generally so we have no way at present of knowing how viable the process is commercially. Cement backers, Brazilian firm Votorantim, are certainly excited by the project even if only for the sustainability kudos it gives them. Director Edvaldo Araújo Rabello presented the project as one of the company's highlights at a keynote presentation at the 6°CBC Congresso do Cimento held in São Paulo, Brazil in May 2014.

One hurdle for the St Marys pilot is the relative lack of light, a required input for algae photosynthesis, even in Canada's most southerly state. Pond Biofuels have reportedly dodged this by using continuously flashing LEDs to simulate artificially short days that encourage growth. On paper or powerpoint a process that could potentially cut even a proportion of CO₂ emissions from a cement plant sounds enticing. Yet if it creates more CO₂ than it saves, through electricity requirements for example, than it isn't worth using.

This is probably what shelved Lafarge's Carbon Capture and Transformation project. It ran a pilot project at its Val d'Azergues plant in France in 2009 with Salata GmbH. The pilot worked but the researchers decided that new advances in processes and biotechnology were required to make the economic and environmental results better. Other companies have also had problems. Holcim started its Aurantia – GreenFuel project in late 2007 at its Jerez cement plant in Spain, backing it with an investment US$92m. This project stalled when GreenFuel shut in 2009 citing lack of funding as the recession hit.

ACC in India also reportedly started its own algae project in 2007, mentioning it in its sustainability report, but nothing more has been reported since. Since this burst of interest InterCement has invested US$2.5m towards algae research in 2013 working with the Federal University of São Carlos, the Federal University of Santa Maria and Algae Biotecnologia.

Algae-based carbon projects for cement plants may remain stuck in the research stage but the market for biofuels continues to grow. For example, this week we report that Ohorongo Cement in Namibia plans to increase its use of blackthorn as a biofuel to use as an alternative fuel in co-processing. The prospects of turning waste CO₂ into a valuable commodity remains uncertain, but the rewards are great. Let's wait and see what St Marys can do.

Canada: Pond Biofuels has set up a bioreactor pilot plant at St Marys cement plant in St Marys, Ontario. The raw smokestack gas from the cement plant is recycled to grow algae in a third-generation 25,000L bioreactor at the on-site pilot plant. The resulting algae can be used for bio-oil, food, fertiliser and sewage treatment.

The algae consume CO₂, NO_X and SO_X from the smokestack gas. Every 1kg of algae produced prevents 2kg of CO₂ from being emitted into the atmosphere. The St Marys Cement Plant produces 720,000t/yr of cement and 540,000t/yr of CO₂. Currently, Pond Biofuels only uses a small portion of the total CO₂ output.

"We consider ourselves a carbon recycling technology," said Steve Martin, founder of Pond Biofuels.

The algae thrive in light filled, CO₂-rich conditions, which are provided in the bioreactor. The light comes from custom-designed red LED lights that flash continuously. The rapid flashing fools the algae into thinking the days are very short, so it grows very fast. "The algae evolve quite quickly; we can get four, five, six generations of algae in a day," said Martin.

Proving the production of algae at commercial scale is important, but the other important part is finding a market for the algae. "Between 10 – 20% of it is oil that be used for producing biodiesel," said Martin. It could also be used a coal replacement, a soil amendment or even animal feed and it can be easily dried using waste heat from the cement plant.