Indian Institute of Petroleum

This chapter explores the potential of algae-derived biocrude as a sustainable alternative to fossil fuels when upgraded, addressing the global need for lower-carbon transportation solutions. Hydrothermal liquefaction (HTL) is highlighted as an emerging and efficient process for converting algae into energy-dense biocrude, utilizing its desirable high lipid content, rapid growth, and carbon sequestration capabilities compared to other HTL feeds. The persisting challenges of algal biocrude, including its high oxygen as well as nitrogen content, are discussed alongside upgrading techniques such as hydrotreatment, catalytic cracking, and esterification, among other experimentally emerging methods. Strategies like blending and co-refining with petroleum refinery feeds during upgradation are shown as cost-effective approaches to enhance biocrude quality, overcome technical/economic challenges, and accelerate integration into existing refinery infrastructure. The chapter also examines the technoeconomic and environmental implications of algae biocrude production and upgrading, emphasizing the need for advancements in catalysts, renewable hydrogen production, and by-product recycling. While economic and technical hurdles remain due to its infancy, algae biocrude-derived fuels offer significant promise in reducing greenhouse gas emissions, enhancing energy security, and contributing to the growing bioeconomy. By combining technological innovations with supportive policies and incentives, algae-derived fuels can play a pivotal role in achieving a sustainable energy future.

The pore network system, defined by Pore Size Distribution (PSD), geometry, and connectivity, plays a crucial role in controlling the storage and transport behavior of shale gas. Despite extensive investigations of shale formations across various Indian basins, pore characterization studies in the Lesser Himalaya remain largely unexplored. In particular, the Neoproterozoic Krol shale from the northwestern Lesser Himalaya represents one of the untapped units with promising gas-bearing characteristics. In this study, shale samples from the Krol Formation were systematically analyzed for pore characteristics across nano- to macro-scales using a combination of Low-Pressure Gas Adsorption (LPGA) with N2 and CO2, Small-Angle X-ray Scattering (SAXS), Field Emission Scanning Electron Microscopy (FE-SEM), and Micro-Computed Tomography (Micro-CT). LPGA N2 adsorption exhibited Type IIB isotherms with H3 hysteresis loops, indicating slit- and wedge-shaped mesopores, while CO2 adsorption revealed Type I isotherms, reflecting micropore filling. PSD derived from LPGA showed bimodal and multimodal patterns using Barrett–Joyner–Halenda (BJH) and Density Functional Theory (DFT) models, respectively. SAXS, sensitive to both open and closed pores, effectively captured the PSD, and the Porod–Debye Scattering Profile (PDSP) model confirmed the dominance of mesopores. FE-SEM observations revealed irregular to elongated nanopores (37–54 nm) and a moderately complex pore structure, as supported by fractal dimensions derived from LPGA, SAXS, and FE-SEM. Micro-CT analysis further indicated the presence of macropores and fractures (≥103 nm), with a mean Feret diameter of 0.07 mm and a pore volume of 0.02 mm3. Porosity values estimated from SAXS, FE-SEM, and micro-CT were 4.98%, 5.64%, and 4.55%, respectively. This integrated multiscale characterization, bridging nano to macroscale pore systems, provides new insights into the storage and transport behavior of gas and emphasizes the Krol shale as a future shale gas formation in the Lesser Himalaya.

Ensuring easy access to clean and safe drinking water using low-cost technology is essential to mitigate the rising water scarcity in emerging economies. Commercial large-scale desalination technologies need significant investment, making them unsuitable for off-grid and small-scale applications. However, this operation can be carried out using a low-cost desalination technology based on renewable energy, known as the solar still. In this research work, a modified basin solar still (basin solar still + internal mirrors + 8 kg gravel + black ink (400 ppm per litre)) was developed and experimentally tested in Visakhapatnam (17.68°N, 83.22°E), India, to determine its appropriateness for sustainable seawater desalination. It produced 14% to 23% more desalinated water than a conventional basin solar still. In addition, its thermal efficiency was between 41% and 42%, which was significantly greater than other basin solar stills reported in literature. In addition, high-quality desalinated water was generated at a cost that was around three times less than the drinking water offered at Indian Railways kiosks. Moreover, the ability to mitigate significant CO2 emissions while also addressing water scarcity demonstrated that the modified basin solar still continues to contribute effectively to the United Nations Sustainable Development Goal 6 (Clean Water and Sanitation).

Ensuring easy access to clean and safe drinking water using low-cost technology is essential to mitigate the rising water scarcity in emerging economies. Commercial large-scale desalination technologies need significant investment, making them unsuitable for off-grid and small-scale applications. However, this operation can be carried out using a low-cost desalination technology based on renewable energy, known as the solar still. In this research work, a modified basin solar still (basin solar still + internal mirrors + 8 kg gravel + black ink (400 ppm per litre)) was developed and experimentally tested in Visakhapatnam (17.68°N, 83.22°E), India, to determine its appropriateness for sustainable seawater desalination. It produced 14% to 23% more desalinated water than a conventional basin solar still. In addition, its thermal efficiency was between 41% and 42%, which was significantly greater than other basin solar stills reported in literature. In addition, high-quality desalinated water was generated at a cost that was around three times less than the drinking water offered at Indian Railways kiosks. Moreover, the ability to mitigate significant CO2 emissions while also addressing water scarcity demonstrated that the modified basin solar still continues to contribute effectively to the United Nations Sustainable Development Goal 6 (Clean Water and Sanitation).

Abstract The proposed cascade control design for both minimum and non-minimum phase delayed time processes is based on the keeping the open loop transfer function same. The controller parameters are interms of the tuning paramter and process parameters for both primary and secondary time delayed processes. The proposed controller parameters having tuning paramters and are tuned based on the desired robust stability factor Ms. Numurous different order minimum and non minimum processes are tested by the proposed method and four examples are presented to show the effectiveness of the proposed method. The proposed method have evaluated based on the integral error creteria such as ITSE, ISE, ITAE and IAE values with desired robustness. The proposed method have compared with the recent literature methods and gives improved performance both unperturbed and purturbed processes. The proposed technique was validated on the cascade experimental setup and outcomes demonstrated significant improvements in performance.

Ensuring easy access to clean and safe drinking water using low-cost technology is essential to mitigate the rising water scarcity in emerging economies. Commercial large-scale desalination technologies need significant investment, making them unsuitable for off-grid and small-scale applications. However, this operation can be carried out using a low-cost desalination technology based on renewable energy, known as the solar still. In this research work, a modified basin solar still (basin solar still + internal mirrors + 8 kg gravel + black ink (400 ppm per litre)) was developed and experimentally tested in Visakhapatnam (17.68°N, 83.22°E), India, to determine its appropriateness for sustainable seawater desalination. It produced 14% to 23% more desalinated water than a conventional basin solar still. In addition, its thermal efficiency was between 41% and 42%, which was significantly greater than other basin solar stills reported in literature. In addition, high-quality desalinated water was generated at a cost that was around three times less than the drinking water offered at Indian Railways kiosks. Moreover, the ability to mitigate significant CO2 emissions while also addressing water scarcity demonstrated that the modified basin solar still continues to contribute effectively to the United Nations Sustainable Development Goal 6 (Clean Water and Sanitation).

Ensuring easy access to clean and safe drinking water using low-cost technology is essential to mitigate the rising water scarcity in emerging economies. Commercial large-scale desalination technologies need significant investment, making them unsuitable for off-grid and small-scale applications. However, this operation can be carried out using a low-cost desalination technology based on renewable energy, known as the solar still. In this research work, a modified basin solar still (basin solar still + internal mirrors + 8 kg gravel + black ink (400 ppm per litre)) was developed and experimentally tested in Visakhapatnam (17.68°N, 83.22°E), India, to determine its appropriateness for sustainable seawater desalination. It produced 14% to 23% more desalinated water than a conventional basin solar still. In addition, its thermal efficiency was between 41% and 42%, which was significantly greater than other basin solar stills reported in literature. In addition, high-quality desalinated water was generated at a cost that was around three times less than the drinking water offered at Indian Railways kiosks. Moreover, the ability to mitigate significant CO2 emissions while also addressing water scarcity demonstrated that the modified basin solar still continues to contribute effectively to the United Nations Sustainable Development Goal 6 (Clean Water and Sanitation).