It is now widely accepted that microalgae are promising candidate feedstocks for biofuel production, especially for biodiesel. Microalgae consist of a vast number of species that contain complex chemical constituents and physical structures. The purpose of this study is to understand the physical and chemical properties of selected microalgae, which is critical to the design of appropriate processes for commercial biofuel production. ASTM standard methods were implemented to examine the microalgae properties, including proximate and ultimate analyses. Among the microalgae studied, green microalgae have more volatile matter than brown microalgae, while the latter contain much higher ash content (as high as 43.4%wt ±0.20%wt dry basis). The lowest ash content was found in the samples of green microalgae (14.3%wt ±0.10%wt dry basis). Ultimate analysis showed that brown microalgae have less carbon content (approx. 25%wt dry basis) as compared to green microalgae (49%wt to 58%wt dry basis). All samples of microalgae were high in sulfur content (0.4%wt to 1.0%wt dry basis). Mineral contents of all microalgal samples were similar to those commonly present in other biomass. Brown microalgae contain significantly higher amounts of carbohydrates (72.9%wt to 75.5%wt dry basis) than green microalgae. On the other hand, green microalgae contain more crude fat (17.1%wt to 27.8%wt dry basis) than brown microalgae. The fatty acid profiles show that the primary fatty acids in microalgal lipids are similar to those of vegetable oils such as soybean oil. However, there are also many odd-numbered fatty acids, such as C15:0, C17:0, and C19:0, which are not typically seen in other seed oils.

Methanol treatment of ponderosa pine wood was performed in a batch reactor at temperatures close to and above the critical points of methanol (238°C and 8.3 MPa) to induce wood degradation into its monomeric and oligomeric components. The resultant methanol soluble and insoluble residues and gases were collected. The volatile components of the liquid and gaseous fractions were analyzed by GC-MS. The gases consisted mostly of carbon dioxide and simple aliphatic hydrocarbons. The non-volatile methanol soluble components were analyzed by HPLC and size exclusion chromatography. The mixture was found to be promising as a source of raw materials for fuel and chemical manufacturing. It consists of a blend of carbohydrate and lignin derived compounds and extractives in varying concentrations depending on the reaction conditions. More extractive compounds were found in the subcritical runs. In mild supercritical conditions the yield of lignin monomers and oligomers was increased, while under severe supercritical treatment, lignin and carbohydrate derived compounds were prevalent.

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Dairy manure contains high concentrations of unutilized phosphorus which is not only a waste of resources but also a burden to dairy farmers and a threat to our environment. Phosphorus cycling and reuse would have a great impact on the dairy industry and agricultural economy as whole. Hydrochar possesses better biological properties when used for soil improvement and carbon sequestration. When produced from dairy manure, hydrochar can attain more than 90% of the total phosphorus content in manure and thus serves as an efficient vehicle for recycling nutrients from waste streams back to the crop system. Research findings prove that hydrochar from dairy manure is scientifically feasible and technologically promising as a vehicle for phosphorus recycling from waste to cropland.

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