The acceptance of liquefied petroleum gas (LPG) cookstove has increased across the country in recent years; however, their performance has not been investigated and established. To achieve this, laboratory tests were carried out to evaluate the thermal efficiency, and industrial combustion analyser (E-instrument E8500) was then used to characterize and quantify the air emissions from combustion of conventional LPG cookstoves in the country. The average thermal efficiency for all tested burners was 66.267 ± 7.218% meeting Tier 4 of the International Organization for Standardization, International Workshop Agreement 11. The mean concentration of CO, NO_x, HC, and SO₂ was in the range of 3–530, 48–810.5, 99–4176, and 0–4,respectively,and the range of CO₂ was 1,792–3,592 mg/m³,which were compared with stationary source limit by Federal Ministry of Environment Standard, Nigeria. The toxicity potential of NO_x and SO₂ was below unity, 25% of the burners tested were below unity for CO, and HC was higher than unity for all tested burners. Most cookstoves met the guidelines for CO, NOx, and SO₂. Hence, LPG in Nigeria could serve as a source of energy for cooking.

In geothermal systems, polymer injection is vital for improving the sweep efficiency of fluid, but the critical challenge is managing the fluid flow in severely fractured systems. Developing stable plugging agents for these systems is a recurring challenge, allowing the loss of the fluid into the large fractures, hence making the recovery very difficult. The fluid is crucial for several applications like power generation, heating, and cooling without producing any toxic emissions. This study presents a gel system formulated with hydroxyethyl cellulose, and a HMTA–resorcinol crosslinker system for harsh conditions of temperature and salinity. The study employed a Central Composite Design (CCD) for optimizing gel formulation. The system achieved optimal conditions at a gelation time of 0.5 h, and the properties were investigated. The experimental outcomes reveal that the polymer gel can exhibit excellent stability under harsh conditions, withstanding temperatures up to 352 °C. This confirms the robustness of the plugging agent at elevated temperatures. This study offers a sustainable and efficient solution for fluid flow control in severely fractured geothermal systems.

Air pollution control is a safe method for achieving a sustainable environment and can be accomplished by adequately monitoring pollutants that pose significant environmental risks. The combustion of sulfur-containing petroleum products has been a major concern for several decades. Therefore, this study was aimed at determining sulfur levels in refined petroleum products such as Premium Motor Spirit (PMS), Automotive Gas Oil (AGO), and Dual-Purpose Kerosene (DPK). It also investigated the air quality implications of sulfur levels and estimated the contribution of the refinery’s products to sulfur dioxide air emission. Fuel samples were collected from the Warri Refining and Petrochemical Company (WRPC) in Nigeria and analyzed using Ultraviolet-visible spectrophotometer (UV-Vis) and Energy-Dispersive X-ray Fluorescence (EDXRF). Sulfur levels were determined at 425 nm wavelength, and sulfur dioxide air emission were estimated for seven consecutive years from 2010 to 2016 using the emission factor approach. The densities of PMS, AGO, and DPK were 0.77 kg/l, 0.832 kg/l, and 0.82 kg/l respectively. The levels of sulfur in PMS, AGO, and DPK were 2.007 x 10^-4 %, 6.970 x 10^-5 wt%, and 4.233 x 10^-5 wt% respectively from UV-Vis technique and 0.016, 0.087 and 0.029% respectively for EDXRF technique were found below the sulfur limit of 0.015 %, 0.005 % and 0.015 % for PMS, AGO and DPK respectively specified by Standard Organization of Nigeria (SON) specifications of 0.1, 0.5 and 0.15wt% for PMS, AGO and DPK respectively. The annual sulfur dioxide emissions were obtained for seven consecutive years from 2010 to 2016. The results from UV-VIS were observed to have the highest SO₂ emission of 0.1718 tons for PMS in 2011, 0.2593 tons in 2010 for AGO, and 0.0974 tons for DPK in 2010, while the lowest emission was observed to be 0.029 tons for PMS in 2015, 0.0362 tons in 2015 for AGO and 0.0181 tons for DPK also in 2015. The results from EDXRF technique were observed to have the highest SO₂ emission of 13.6939 tons for PMS in 2012, 323.6881 tons for AGO in 2010, and 66.7147 tons for DPK also in 2010, while the lowest emissions for PMS, AGO and DPK were all observed in 2015 to be 2.3122, 45.1872, and 12.4182 tons respectively. The study concluded that the refinery complied with the set requirements.